For the new year, I wanted to start with a fish that is one of my personal favorites. I present to you the Bowfin (Amia calva). Depending on where you find them, they are also called grinnel, choupique, mudfish, or swamp trout. These fish are a native species and the only surviving member of their family (Amiidae) and ancient group, the Halecomorphs. The Halecomorphs appeared around 250 million years ago during the Early Triassic which is why Bowfin are considered an “ancient fish” and even relicts. Their defining characters are the following: a head covered in bony plates with two protruding tube-like nostrils, a mouth full of sharp teeth, an elongated dorsal fin that undulates, and a rounded (technically, partially heterocercal) caudal fin. Their bodies are often olive or green in color but can be brown, with dark net-like mottling on the sides. Males and juveniles will have a black “eye spot” on the caudal base encircled by an orange ring, and females will have a reduced or non-existent spot. Fun fact, if they are kept moist, Bowfin can survive out of water for up to 24 hours due to their specialized air bladder that can act as a lung when in low-oxygen conditions.
Image of a juvenile Bowfin showing the defining characteristics. Captured during a survey in a Lake Erie lacustuary, Ohio. Credit: Paul DeRolf
Bowfin reside in various habitat types, primarily ones associated with rivers. The most common places to find them are oxbows and floodplain lakes, but they also live in glacial lakes and wetlands, along with lacustuary zones of the Great Lakes. They are associated with dense beds of aquatic vegetation but when those are sparse, they will utilize other structures such as woody debris or other organic matter.
Typical habitat for Bowfin. Backwater wetland off the river in northeastern IL. Credit: Paul DeRolf
For the most part, Bowfin are an ambush-style predator. They will hide within the vegetation and wait for their prey to move. Once the prey item is within reach, they will strike with great speed and power to grab the meal. If they aren’t ambushing, they are out cruising the shallows searching for the food. Their primary food sources are fish, crayfish, and even small, terrestrial animals that fall into the water. Historically, the eating habits of Bowfin have landed them in hot water, we will circle back to this.
Image of a Bowfin showing the protruding, tube-like nostrils. Captured during a survey in an oxbow lake of the Lower Wabash River, IN.
For the spawning season, males turn a bright green over their bodies and even blueish-green in their mouths. They will build circular nests up to 36 inches in diameter within dense vegetation or around woody structures. Once the female lays her eggs, she moves out into deeper water to recover while the male guards the nest. Once the eggs hatch, the young form feeding schools, also known as “bowfin balls,” and the males will vigorously defend them. There has been documentation of males launching themselves out of the water at Great Blue Herons and other shoreline predators that threatened the young. Once the female has recovered, they establish a perimeter around the male to keep larger, aquatic predators from sneaking in. I witnessed a Northern Pike get hit on the gill plate and killed by a female Bowfin for getting too far inside her area.
Image of a female Bowfin from northeastern Il.
Bowfin have a wide native range that spans from the headwaters of the Mississippi, down to the Gulf Coast, up the Atlantic shore, and around the Great Lakes. They are outside this range, either from natural movement or human introduction. Overall, their population is status is of “least concern,” but in most parts of their range they are treated like “trash.” Because they eat other fish like Bluegill or Largemouth Bass, many think they “decimate” these populations or “ruin lakes.” It eventually caused people to remove Bowfin from the lakes and rivers in large quantities, mainly through bowfishing but also by hook-and-line. No evidence shows that Bowfin eat more fish than Musky, Northern Pike, or even Largemouth Bass, but they happen to be the target because they aren’t a “sport fish.” Recently, Bowfin have gained a lot of recognition and support in their favor from a growing community of outdoor enthusiasts. This community is working towards better management practices to be put in place to regulate the harvest of Bowfin to keep the populations intact and aquatic ecosystems balanced.
Map from the USGS showing the range of Bowfin. Native areas are in orange and introduced locations are in red.
The best way to observe Bowfin is to fish for them. Pound-for-pound, they are one of the hardest-fighting fish out there and will make you work for the catch. You can also snorkel in the shallows around vegetation or other structure to get face-to-face with these primitive fish. Even though they are aggressive eaters, they do not attack humans and are much more afraid of you than you are of them. No matter how you decide to see them, remember to make sure that you enjoy, protect, and enhance our freshwater ecosystems!
*Please note that Bowfin, a native fish, are often confused and misidentified with the non-native Snakehead, so please be aware of what you are handling and do not transport fish outside their current range.
Image from the Northwest Ohio Anglers Association
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